Infectious diseases often result from invasion of the body by pathogenic microorganisms including bacteria, fungi and viruses. Over the years, many chemistries and methods have been developed to kill or inhibit the growth of pathogenic microorganisms including the development and use of antibiotics, antiviral agents and oxidizing agents. Electromagnetic radiation in many wavelength ranges has also been used. It is known that pathogenic microorganisms may be killed or their growth inhibited by exposure of the microorganisms to light in the presence of oxygen and certain photosensitizers.